{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "%reload_ext autoreload\n",
    "%autoreload 2\n",
    "%matplotlib inline\n",
    "import os\n",
    "os.environ[\"CUDA_DEVICE_ORDER\"]=\"PCI_BUS_ID\";\n",
    "os.environ[\"CUDA_VISIBLE_DEVICES\"]=\"0\"; "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "import ktrain\n",
    "from ktrain import text"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## STEP 1: Load and Preprocess Data\n",
    "\n",
    "\n",
    "The CoNLL2003 NER dataset can be downloaded from [here](https://github.com/amaiya/ktrain/tree/master/ktrain/tests/conll2003)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "detected encoding: utf-8 (if wrong, set manually)\n",
      "Number of sentences:  14041\n",
      "Number of words in the dataset:  23623\n",
      "Tags: ['B-PER', 'O', 'I-MISC', 'B-ORG', 'I-LOC', 'I-ORG', 'I-PER', 'B-MISC', 'B-LOC']\n",
      "Number of Labels:  9\n",
      "Longest sentence: 113 words\n"
     ]
    }
   ],
   "source": [
    "TDATA = 'data/conll2003/train.txt'\n",
    "VDATA = 'data/conll2003/valid.txt'\n",
    "(trn, val, preproc) = text.entities_from_conll2003(TDATA, val_filepath=VDATA)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## STEP 2: Define a Model"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "In this example notebook, we will build a Bidirectional LSTM model that employs the use of [pretrained BERT word embeddings](https://arxiv.org/abs/1810.04805).  By default, the `sequence_tagger` will use a pretrained multilingual model (i.e., `bert-base-multilingual-cased`) that supports 157 different languages.  However, since we are training a English-language model on an English-only dataset, it is better to select the English pretrained BERT model: `bert-base-cased`. Notice that we selected the **cased** model, as case is important for English NER, as entities are often capitalized.  A full list of available pretrained models is [listed here](https://huggingface.co/transformers/pretrained_models.html).  *ktrain* currently supports any `bert-*` model in addition to any `distilbert-*` or `albert-*` model. One can also employ the use of BERT-based [community-uploaded moels](https://huggingface.co/models) that focus on specific domains such as the biomedical or scientific  domains (e.g, BioBERT, SciBERT). To use SciBERT, for example, set `bert_model` to `allenai/scibert_scivocab_uncased`. "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "bilstm: Bidirectional LSTM (https://arxiv.org/abs/1603.01360)\n",
      "bilstm-bert: Bidirectional LSTM w/ BERT embeddings\n",
      "bilstm-crf: Bidirectional LSTM-CRF  (https://arxiv.org/abs/1603.01360)\n",
      "bilstm-elmo: Bidirectional LSTM w/ Elmo embeddings [English only]\n",
      "bilstm-crf-elmo: Bidirectional LSTM-CRF w/ Elmo embeddings [English only]\n"
     ]
    }
   ],
   "source": [
    "text.print_sequence_taggers()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Embedding schemes employed (combined with concatenation):\n",
      "\tword embeddings initialized randomly\n",
      "\tBERT embeddings with bert-base-cased\n",
      "\n"
     ]
    }
   ],
   "source": [
    "model = text.sequence_tagger('bilstm-bert', preproc, bert_model='bert-base-cased')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "From the output above, we see that the model is configured to use both BERT pretrained word embeddings and randomly-initialized word emeddings. Instead of randomly-initialized word vectors, one can also select pretrained fasttext word vectors from [Facebook's fasttext site](https://fasttext.cc/docs/en/crawl-vectors.html) and supply the URL via the `wv_path_or_url` parameter:\n",
    "```python\n",
    "wv_path_or_url='https://dl.fbaipublicfiles.com/fasttext/vectors-crawl/cc.en.300.vec.gz')\n",
    "```\n",
    "We have not used fasttext word embeddings in this example - only BERT word embeddings."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "learner = ktrain.get_learner(model, train_data=trn, val_data=val, batch_size=128)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## STEP 3: Train and Evaluate Model"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "preparing train data ...done.\n",
      "preparing valid data ...done.\n",
      "Train for 110 steps, validate for 26 steps\n",
      "Epoch 1/10\n",
      "110/110 [==============================] - 61s 551ms/step - loss: 0.1072 - val_loss: 0.0301\n",
      "Epoch 2/10\n",
      "110/110 [==============================] - 54s 489ms/step - loss: 0.0280 - val_loss: 0.0214\n",
      "Epoch 3/10\n",
      "110/110 [==============================] - 53s 486ms/step - loss: 0.0159 - val_loss: 0.0179\n",
      "Epoch 4/10\n",
      "110/110 [==============================] - 54s 487ms/step - loss: 0.0104 - val_loss: 0.0165\n",
      "Epoch 5/10\n",
      "110/110 [==============================] - 53s 484ms/step - loss: 0.0087 - val_loss: 0.0161\n",
      "Epoch 6/10\n",
      "110/110 [==============================] - 53s 481ms/step - loss: 0.0129 - val_loss: 0.0176\n",
      "Epoch 7/10\n",
      "110/110 [==============================] - 53s 480ms/step - loss: 0.0094 - val_loss: 0.0167\n",
      "Epoch 8/10\n",
      "110/110 [==============================] - 53s 481ms/step - loss: 0.0060 - val_loss: 0.0164\n",
      "Epoch 9/10\n",
      "110/110 [==============================] - 53s 485ms/step - loss: 0.0041 - val_loss: 0.0155\n",
      "Epoch 10/10\n",
      "110/110 [==============================] - 53s 486ms/step - loss: 0.0033 - val_loss: 0.0157\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "<tensorflow.python.keras.callbacks.History at 0x7fe9c18f8470>"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "learner.fit(0.01, 2, cycle_len=5)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "   F1: 92.62\n",
      "           precision    recall  f1-score   support\n",
      "\n",
      "     MISC       0.84      0.84      0.84       922\n",
      "      PER       0.96      0.96      0.96      1842\n",
      "      LOC       0.95      0.96      0.96      1837\n",
      "      ORG       0.88      0.92      0.90      1341\n",
      "\n",
      "micro avg       0.92      0.93      0.93      5942\n",
      "macro avg       0.92      0.93      0.93      5942\n",
      "\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "0.9262014208106979"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "learner.validate()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We can use the `view_top_losses` method to inspect the sentences we're getting the most wrong. Here, we can see our model has trouble with titles, which is understandable since it is mixed into a catch-all miscellaneous category."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "total incorrect: 11\n",
      "Word            True : (Pred)\n",
      "==============================\n",
      "The            :O     (O)\n",
      "titles         :O     (O)\n",
      "of             :O     (O)\n",
      "his            :O     (O)\n",
      "other          :O     (O)\n",
      "novels         :O     (O)\n",
      "translate      :O     (O)\n",
      "as             :O     (O)\n",
      "\"              :O     (O)\n",
      "In             :B-MISC (O)\n",
      "the            :I-MISC (O)\n",
      "Year           :I-MISC (O)\n",
      "of             :I-MISC (I-MISC)\n",
      "January        :I-MISC (O)\n",
      "\"              :O     (O)\n",
      "(              :O     (O)\n",
      "1963           :O     (O)\n",
      ")              :O     (O)\n",
      ",              :O     (O)\n",
      "\"              :O     (O)\n",
      "The            :B-MISC (O)\n",
      "Collapse       :I-MISC (O)\n",
      "\"              :O     (O)\n",
      "(              :O     (O)\n",
      "1964           :O     (O)\n",
      ")              :O     (O)\n",
      ",              :O     (O)\n",
      "\"              :O     (O)\n",
      "Sleeping       :B-MISC (B-MISC)\n",
      "Bread          :I-MISC (I-MISC)\n",
      "\"              :O     (O)\n",
      "(              :O     (O)\n",
      "1975           :O     (O)\n",
      ")              :O     (O)\n",
      ",              :O     (O)\n",
      "\"              :O     (O)\n",
      "The            :B-MISC (O)\n",
      "Decaying       :I-MISC (B-MISC)\n",
      "Mansion        :I-MISC (I-MISC)\n",
      "\"              :O     (O)\n",
      "(              :O     (O)\n",
      "1977           :O     (O)\n",
      ")              :O     (O)\n",
      "and            :O     (O)\n",
      "\"              :O     (O)\n",
      "A              :B-MISC (B-MISC)\n",
      "World          :I-MISC (I-MISC)\n",
      "of             :I-MISC (I-MISC)\n",
      "Things         :I-MISC (O)\n",
      "\"              :O     (O)\n",
      "(              :O     (O)\n",
      "1982           :O     (O)\n",
      ")              :O     (O)\n",
      ",              :O     (O)\n",
      "followed       :O     (O)\n",
      "by             :O     (O)\n",
      "\"              :O     (O)\n",
      "The            :B-MISC (O)\n",
      "Knot           :I-MISC (O)\n",
      ",              :O     (O)\n",
      "\"              :O     (O)\n",
      "\"              :O     (O)\n",
      "Soul           :B-MISC (B-MISC)\n",
      "Alone          :I-MISC (I-MISC)\n",
      "\"              :O     (O)\n",
      "and            :O     (O)\n",
      ",              :O     (O)\n",
      "most           :O     (O)\n",
      "recently       :O     (O)\n",
      ",              :O     (O)\n",
      "\"              :O     (O)\n",
      "A              :B-MISC (B-MISC)\n",
      "Woman          :I-MISC (I-MISC)\n",
      ".              :O     (O)\n",
      "\"              :O     (O)\n",
      "\n",
      "\n"
     ]
    }
   ],
   "source": [
    "learner.view_top_losses(n=1)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Make Predictions on New Data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [],
   "source": [
    "predictor = ktrain.get_predictor(learner.model, preproc)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[('As', 'O'),\n",
       " ('of', 'O'),\n",
       " ('2019', 'O'),\n",
       " (',', 'O'),\n",
       " ('Donald', 'B-PER'),\n",
       " ('Trump', 'I-PER'),\n",
       " ('is', 'O'),\n",
       " ('still', 'O'),\n",
       " ('the', 'O'),\n",
       " ('President', 'O'),\n",
       " ('of', 'O'),\n",
       " ('the', 'O'),\n",
       " ('United', 'B-LOC'),\n",
       " ('States', 'I-LOC'),\n",
       " ('.', 'O')]"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "predictor.predict('As of 2019, Donald Trump is still the President of the United States.')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [],
   "source": [
    "predictor.save('/tmp/mypred')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [],
   "source": [
    "reloaded_predictor = ktrain.load_predictor('/tmp/mypred')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[('Paul', 'B-PER'),\n",
       " ('Newman', 'I-PER'),\n",
       " ('is', 'O'),\n",
       " ('my', 'O'),\n",
       " ('favorite', 'O'),\n",
       " ('actor', 'O'),\n",
       " ('.', 'O')]"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "reloaded_predictor.predict('Paul Newman is my favorite actor.')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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